Pen Boutique Blog - Thoughts, expressions and news about pen world!

Pen Boutique Blog is a day to day experiences that we would like to share with our customers and readers.

Showing posts with label ink formula. Show all posts
Showing posts with label ink formula. Show all posts
Wednesday, July 8, 2015

Ink Trivia Government Ink

›
Question: What ink formula is the standard for use in the United States Post Office? Answer: 11.7 grams of tannic acid, 3.8 ...
›
Home
View web version
Powered by Blogger.